This read-only attribute is a space separated list of all the conditions names recognized by the Warnings attribute. The names are listed below.

FitsChan

The following conditions are currently recognised (all are case-insensitive):

• " BadCel" : This condition arises when reading a FrameSet from a non-Native encoded FitsChan if an unknown celestial co-ordinate system is specified by the CTYPE keywords.

• " BadCTYPE" : This condition arises when reading a FrameSet from a non-Native encoded FitsChan if an illegal algorithm code is specified by a CTYPE keyword, and the illegal code can be converted to an equivalent legal code.

• " BadKeyName" : This condition arises if a FITS keyword name is encountered that contains an illegal character (i.e. one not allowed by the FITS standard).

• " BadKeyValue" : This condition arises if the value of a FITS keyword cannot be determined from the content of the header card.

• " BadLat" : This condition arises when reading a FrameSet from a non-Native encoded FitsChan if the latitude of the reference point has an absolute value greater than 90 degrees. The actual absolute value used is set to exactly 90 degrees in these cases.

• " BadMat" : This condition arises if the matrix describing the transformation from pixel offsets to intermediate world coordinates cannot be inverted. This matrix describes the scaling, rotation, shear, etc., applied to the pixel axes, and is specified by keywords such as PCi_j, CDi_j, CROTA, etc. For example, the matrix will not be invertable if any rows or columns consist entirely of zeros. The FITS-WCS Paper I " Representation of World Coordinates in FITS" by Greisen & Calabretta requires that this matrix be invertable. Many operations (such as grid plotting) will not be possible if the matrix cannot be inverted.

• " BadPV" : This condition arises when reading a FrameSet from a non-Native encoded FitsChan. It is issued if a PVi_m header is found that refers to a projection parameter that is not used by the projection type specified by CTYPE, or the PV values are otherwise inappropriate for the projection type.

• " BadVal" : This condition arises when reading a FrameSet from a non-Native encoded FitsChan if it is not possible to convert the value of a FITS keywords to the expected type. For instance, this can occur if the FITS header contains a string value for a keyword which should have a floating point value, or if the keyword has no value at all (i.e. is a comment card).

• " Distortion" : This condition arises when reading a FrameSet from a non-Native encoded FitsChan if any of the CTYPE keywords specify an unsupported distortion code using the " 4-3-3" format specified in FITS-WCS paper IV. Such distortion codes are ignored.

• " NoCTYPE" : This condition arises if a default CTYPE value is used within AST_READ, due to no value being present in the supplied FitsChan. This condition is only tested for when using non-Native encodings.

• " NoEquinox" : This condition arises if a default equinox value is used within AST_READ, due to no value being present in the supplied FitsChan. This condition is only tested for when using non-Native encodings.

• " NoRadesys" : This condition arises if a default reference frame is used for an equatorial co-ordinate system within AST_READ, due to no value being present in the supplied FitsChan. This condition is only tested for when using non-Native encodings.

• " NoLonpole" : This condition arises if a default value is used for the LONPOLE keyword within AST_READ, due to no value being present in the supplied FitsChan. This condition is only tested for when using non-Native encodings.

• " NoLatpole" : This condition arises if a default value is used for the LATPOLE keyword within AST_READ, due to no value being present in the supplied FitsChan. This condition is only tested for when using non-Native encodings.

• " NoMjd-obs" : This condition arises if a default value is used for the date of observation within AST_READ, due to no value being present in the supplied FitsChan. This condition is only tested for when using non-Native encodings.

• " Tnx" : This condition arises if a FrameSet is read from a FITS header containing an IRAF " TNX" projection which includes terms not supproted by AST. Such terms are ignored and so the resulting FrameSet may be inaccurate.

• " Zpx" : This condition arises if a FrameSet is read from a FITS header containing an IRAF " ZPX" projection which includes " lngcor" or " latcor" correction terms. These terms are not supported by AST and are ignored. The resulting FrameSet may therefore be inaccurate.